Commercial solar savings calculator
Enter your electricity spend to estimate the system size, annual saving, payback and year-one tax relief for solar panels for agriculture. Indicative only, not a quote.
Indicative estimate
- Recommended system
- 90 kWp
- Annual saving
- £23,940
- Simple payback
- 3.4 years
- Year-one tax relief (AIA)
- £20,250
- CO₂ saved
- 17.7 t/yr
- 25-year saving
- £598,500
Assumptions: about 900 kWh per kWp per year (UK yields run roughly 800 to 1,000), about 70% of generation used on site even when the system is sized to daytime demand (the rest is exported), exports paid at 4p per kWh (business export rates run roughly 3p to 15p, with the higher rates usually requiring the same supplier to supply your import), install cost of £1,204 per kW up to 50 kW (the DESNZ 2026 median for 10 to 50 kW installs, VAT where applicable) tapering to about £775 per kW at 500 kW (indicative industry pricing, ex VAT, excluding grid, roof and battery costs), Annual Investment Allowance relief at 25% corporation tax, CO2 at the 2026 DESNZ grid factor of 0.131 kg CO2e per kWh, and 0.5% a year panel degradation in the 25-year figure. These are illustrative defaults; your figures depend on roof, shading, load profile, tariff and tax position. This tool does not store any data you enter.
Calculator FAQs
How accurate is this calculator?
It gives an indicative estimate from standard UK assumptions: roughly 900 kWh generated per kWp per year, about 70% of generation used on site, a 4p export rate, and an install cost from £1,204 per kW for small systems tapering to about £775 per kW at 500 kW. Your real figures depend on your roof, orientation, shading, load profile and tariff. For a precise figure, ask the installer to model your half-hourly meter data.
What is self-consumption and why does it matter?
Self-consumption is the share of solar you use on site rather than export. On-site use saves the full electricity price, while exported units earn only the lower Smart Export Guarantee rate, so a higher daytime load means a shorter payback. The slider lets you set your daytime usage share.
Does the estimate include tax relief?
Yes. Commercial solar usually qualifies as plant and machinery, so we show indicative year-one Annual Investment Allowance relief at the 25% corporation tax rate. Your actual eligibility depends on your tax position and profits.
Is this a quote?
No. It is an indicative estimate to help you scope the opportunity. A real proposal needs your meter data, a roof assessment and a grid check, which the installer your enquiry is passed to should carry out before quoting.